Noise features in InP crystals operating under static, periodic or fluctuating electric fields

The results of a study concerning the intrinsic noise in low-doped n-type InP crystals operating under static, periodic or fluctuating electric fields are shown. To simulate the dynamics of electrons in the bulk, we employ a Monte Carlo approach, by taking into account the main details of band structure, scattering processes, as well as heating effects. The noise features are investigated by computing the velocity fluctuations correlation function, its spectral density and the total noise power, for different values of amplitude and frequency of the driving field. We show how the noise spectra are affected by the electric field frequency and compare their peculiarities with those exhibited in the static field case. Preliminary findings obtained in InP crystals driven by an electric field fluctuating for the superimposition of a correlated noise source are discussed and compared with those previously obtained in GaAs bulks. Our results confirm that the diffusion noise in low-doped semiconductors can be reduced by the addition of a fluctuating component to the driving electric field and that this effect critically depends on the characteristic times of the external noise.